Background: Type I diabetes mellitus (TIDM) is an emerging public health issue; in which the 
relation between quality of sleep (QoS) and glycemic control is inconsistent; where inadequate or poor QoS
is associated with higher glycosylated hemoglobin (HbA1c) levels and greater glycemic variability. 
Conversely, altered glucose metabolism may affect sleep quality, suggesting a bidirectional relationship 
between QoS and DM control. Aim of the study: Assess the quality of sleep habits among TIDM patients and 
to assess the relation between quality of sleep habits and glycemic control among type I insulin dependent 
diabetes mellitus patients. Design: A descriptive correlational research design was used to conduct this 
study. Setting: The present study was conducted at: the Inpatient Medical Department and Medical 
Outpatient Clinic at Matrouh General Hospital affiliated to Directorate of Health Affairs in Matrouh .
Subjects: A convenience sample of 120 adult patients with type I diabetes mellitus were recruited in the 
current study. Three tools were utilized for data collection; namely: The Bio-sociodemographic and Clinical 
Data Structured Interview Schedule, Parameters for Glycemic Control Sheet and The Pittsburgh Sleep 
Quality Index (PSQI). Results: More than half of the studied patients suffered from poor QoS ranged from 
moderate to moderate severe difficulties in all area of sleep quality. In addition, a significant relation was 
declared between the global PSQI components score and the HbA1C level in the baseline and second 
researcher's assessment. In conclusion: the TIDM patients are more susceptible to poor sleep quality being
obviously linked with poor glycemic control. Recommendation: Increase diabetic patients' awareness about 
the importance of following proper sleep quality practices in association with sustaining their glycemic 
control.